1. Field of the Invention
The present invention relates to an information processing apparatus that has a function of communicating image data with an external apparatus, a method for controlling the same, a program, and a storage medium.
2. Description of the Related Art
Facsimile machines have been used as tools for transmitting information between offices that are distant from each other. In methods for transmitting information using facsimile machines, data that needs to be transmitted is transmitted as image data via a public switched telephone network (PSTN) line or an integrated services digital network (ISDN) line, and the data is output on recording paper on a receiving side.
A strong demand to reduce the communication costs of facsimile transmission and reception has existed, and various proposals have been made to reduce the communication costs. For example, a method is proposed in Japanese Patent Laid-Open No. 2002-118758, in which, in order to perform two-way facsimile communication in the same call, after facsimile transmission is completed, the transmit mode and receive mode of terminals are interchanged by a receiver sending a transmit-receive switching signal to a sender.
This method is a unique method that is not based on International Telecommunication Union-Telecommunication Standardization Sector (ITU-T) standard T.30. However, in this method, since facsimile transmission and reception can be performed in the same call, no additional connection fee for a return call is necessary. Thus, the communication costs can be reduced.
Moreover, a method is proposed in Japanese Patent Laid-Open No. 6-70070, in which, when a calling side polls a called side and receives data from the called side, the called side also sends documents other than a document subjected to polling to the calling side. In this method, a confidential transmit file and the like, together with a document subjected to polling, can be sent. Thus, in comparison with a case where only a document subjected to polling is sent, in this case, the communication costs can be largely reduced, as in the case shown in Japanese Patent Laid-Open No. 2002-118758.
Facsimile communication according to the known T.30 standard is one-way communication from a calling side to a called side or from the called side to the calling side. An object of the methods proposed in Japanese Patent Laid-Open Nos. 2002-118758 and 6-70070 is to reduce the communication costs under restrictions due to one-way communication.
On the other hand, recently, Internet Protocol (IP) networks based on local area networks (LANs) and the Internet have rapidly become widespread, and known methods for transmitting facsimile information are changing. Specifically, a method has been developed, in which real-time facsimile transmission is performed via IP networks using Session Initiation Protocol (SIP) (refer to Internet Engineering Task Force (IETF) Request for Comment (RFC) 3261) for managing communication sessions and ITU-T standard T.38 (hereinafter called T.38).
An advantage of using real-time facsimile transmission according to SIP and T.38 is that two-way communication in the same call can be performed using SIP, which is universally defined. Thus, in comparison with cases where the aforementioned known methods are adopted, in a case where real-time facsimile transmission according to SIP and T.38 is adopted, the communication costs can be largely reduced taking advantage of two-way communication.
The present invention provides a mechanism to determine whether to transmit image data from a called side to a calling side using a communication session established for transmitting image data from the calling side to the called side, and transmit image data from the called side to the calling side on the basis of the result of the determination.